Part Number:TMS320F28335
逆变器一发波电压采样就不对,电压采样波形出现异常,,实际波形。
电压采样原理图
Yale Li:
我已经咨询了相关工程师:
https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1244094/tms320f28335-there-is-a-problem-with-the-sampling-waveform-after-the-inverter-sends-out-the-wave
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Yeihong LI:
前级电阻是不是太大了
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Yale Li:
I think we are suspecting some noise caused by the inverter switching, is impacting the ADC sample. I'm assuming that the input to the C2000 ADC from the op-amp(and its output R/C) are located close to the C2000 MCU? If you could give some comment here it would be good to know.
We may have to accept that there will be noise due to the switching and move the ADC sample to accommodate. Have you tried to change the trigger for the ADC to happen before the switching action to see if that has a better noise profile? This would confirm that the switching action is what is causing the extra noise on the ADC sample.
Based on the ADC architecture I think we should be safe once the sample has completed and the ADC is converting; but if we are sampling the ADC input while the inverting is switching, we run the risk of sampling noise on top of the signal as you are seeing.